According to estimates by the Federal Environment Agency (UBA), the discharge from the combined sewer system in Germany that is not treated in sewage treatment plants reaches an annual volume of around 1.3 billion cubic metres, while the discharge of precipitation water, which is also not covered by sewage treatment plants, amounts to a volume of just under 4 billion cubic metres. In contrast, about 10 billion cubic metres of wastewater were collected by sewage treatment plants. Around half of the wastewater treated by sewage treatment plants seeps into the environment uncontrolled - and leaves clear traces.
However, it is not only consumers who need to rethink and change their behaviour in dealing with residues from daily consumption and toilet flushing. The solution to the problem can only be found holistically, i.e. if all parts of society join in. In this context, industry is also called upon to be more mindful in its use of raw materials. The researchers also found plastic pellets in three of the four sewage treatment plants examined. In some cases, pellets were even found on roadsides, reports project leader Breitbarth. The construction industry, too, needs to be more careful when dealing with insulation materials such as Styrofoam, whose finely crumbled fragments are dispersed by the wind in all directions.